Hydraulic jet propulsion apparatus suitable for waterborne vessels

ABSTRACT

An hydraulic jet propulsion apparatus, suitable for propelling waterborne vessels, includes a pump for drawing in water through an intake duct, a discharge duct through which water pumped by the pump passes, a steering duct, and a support for the steering duct, which support comprises an outrigger member carried by the discharge duct, whereby the steering duct is positioned adjacent to and downstream of the discharge duct. Water received by the steering duct from the discharge duct discharges to the exterior of the apparatus as a propulsive jet. The steering duct is capable of rotational movement with respect to the discharge duct, to change the direction of the jet for steering purposes, about an axis disposed obliquely to and intersecting the longitudinal axis of the discharge duct. The support for the steering duct and also a steering shaft, connected to the steering duct, which is capable of effecting the rotational movement of the steering duct, are disposed wholly externally of the discharge duct and of the steering duct.

United States Patent Copp et al.

[ Aug. 26, 1975 [75] Inventors: Albert Leslie Copp; George Lancaster Ronson, both of Cheltenham, England [57] ABSTRACT 73 A D H d r U t L d An hydraulic jet propulsion apparatus, suitable for owty y mu m ms mute propelling waterborne vessels, includes a pump forv Cheltenham England drawing in water through an intake duct, a discharge 22 i D 1973 duct through which water pumped by the pump passes, a steering duct, and a support for the steering [2]] Appl' 423588 duct, which support comprises an outrigger member carried by the discharge duct, whereby the steering Foreign Application Priority Data duct is positioned adjacent to and downstream of the Dec 14 1972 United Kingdom I 578O9/72 discharge duct. Water received by the steering duct Dec. 1972 United Kingdom 57810/72 from the discharge duct discharges to the exterior of I I i l the apparatus as a propulsive jet. The steering duct is 52 us. Cl 115/12 R capable of rotational movement with respect to [51] Int. 2 I 1 B63 "0 discharge duct, to change the direction of the jet for [58] Field of Search h I 1 15/11 16 steering purposes, about an axis disposed obliquely to 60/52 222 114/151 and intersecting the longitudinal axis of the discharge duct. The support for the steering duct and also a [56] References Cited steering shaft, connected to the steering duct, which is capable of effecting the rotational movement of the UNITED STATES PATENTS steering duct, are disposed wholly externally of the discharge duct and of the steering duct. a c 3,658,026 4/1972 Jacobson 115/12 R 5 Claims, 4 Drawing Figures --.r.-- ..c 55 13 u ==:=-'=-"====2 87, i 4 32 59 1 .1 I82 12 58 m 2 4 ,g,,29

3 75 2 ik 2 s 43 2 2" as 71 22 0 69 46 45 55 66 67 HYDRAULIC JET PROPULSION APPARATUS SUITABLE FOR WATERBORNE VESSELS Primary Examiner-Trygve M. Blix Assistant ExaminerSherman D. Basinger Attorney, Agent, or Firm-Young & Thompson HYDRAULIC JET PROPULSION APPARATUS SUITABLE FOR WATERBORNE VESSELS This invention relates to hydraulic jet propulsion apparatus, suitable for propelling waterborne vessels, of the kind including a pump for drawing in water through an intake duct and for discharging the water through a discharge duct so that when used for propelling a vessel a jet of water is discharged either into the air or into the water in which the vessel floats. In order to deflect the jet of water issuing from the discharge duct for steering purposes a steering duct is provided being capable of rotational movement with respect to the discharge duct about an axis disposed obliquely to and intersecting the longitudinal axis of the discharge duct. Such an apparatus is hereinafter referred to as an apparatus of the kind described.

According to the invention there is provided an apparatus of the kind described in which support means for the steering duct and drive means for effecting the rotational movement of the steering duct are disposed wholly externally of the discharge duct and the steering duct.

The support means may include a member projecting externally from the wall of, and disposed substantially parallel to the longitudinal axis of, said discharge duct.

The support means may also include a bearing, carried by said member, whose axis is coincident with said obliquely-disposed axis, said bearing supporting a stub shaft carried by said steering duct.

A reversing deflector may be pivotally mounted upon the steering duct and be movable from an inoperative position to an operative position in which it changes the direction of a jet of water discharging from the steering duct.

The reversing deflector may be of part-cylindrical form having said portions by which it is pivotally mounted upon the steering duct.

One embodiment of the invention will now be particularly described by way of example with reference to the accompanying drawings of which,

FIG. 1 is a side elevation of an hydraulic jet propulsion apparatus,

FIG. 2 is a plan view of the apparatus shown in FIG.

FIG. 3 is an enlarged part-cross-sectional view of a part of the apparatus shown in FIGS. 1 and 2, and

FIG. 4 is a part-cross-section taken along the line IV IV on FIG. 3.

With reference to FIGS. 1 and 2 of the drawings, an hydraulic jet propulsion apparatus 10, suitable for propelling a waterborne vessel, includes an intake duct 11, a pump 12 of the axial-flow type whose casing 13 is connected at 14 to the intake duct, and a discharge duct 15 which is connected at 16 to that end of the casing 13 remote from the intake duct.

The pump and the intake duct are shown mounted inboard of a vessel, part of the hull of which is shown at 17, and the intake duct is open to the underside of the vessel by way of an intake aperture 18, so that water can enter the apparatus in the direction of the arrows 19.

The pump is driven in conventional manner by way of shafting 20 taken from an internal combustion engine, in part diagrammatically shown at 21 and mounted inboard of the vessel.

The rearward end, that is the right-hand end in FIG. 1, of the pump casing 13 enters a suitably-shaped aperture 22 formed in the transom 23 of the vessel, the discharge duct 15 extending from this aperture rearwardly of the vessel.

As shown more clearly in FIG. 3, the discharge duct 15 is convergent in the rearward direction and at its rearward end portion the end face 24, which is of annularshape, lies 'in a plane which is disposed obliquely with respect to, and which intersects, the longitudinal axis 25 of the discharge duct. The arrangement is such that the lowermost portion 26 of the rearward end portion of the duct 15 is closest to the pump 12 and the uppermost portion 27 of that end portion is furthest from the pump.

The apparatus includes a steering duct 28, the forward end portion of which has an end face 29, which is of annular shape and disposed in a plane parallel, and so adjacent, to said obliquely-disposed plane that the said rearward end face 24 and said forward end face 29 are co-axial the one with respect to the other. As shown, thesetwo end faces are of the same internal diameter, their common axis being indicated at 30. The rearward end portion of the duct and the forward end portion of the duct 28 have substantially the same cross-sectional dimensions and thus define a substantially constannflow area from that end portion of the duct 15 into the duct 28.

A small annular axial clearance 31 of predetermined size is formed between the two end faces 24 and 29 and a flanged peripheral portion 32 is integrally formed with the discharge duct adjacent to the end face 24 and peripherally shrouds the forward end portion of the steering duct 28.

The steering duct extends rearwardly as shown and towards its end 33 remote from the pump 12 merges into a cross-section of elliptical form when viewed, as in FIG. 4, in a direction along the longitudinal axis of the discharge duct.

In order to support the apparatus with respect to the transom 23 a mounting ring 34 is provided suitably -secured by bolts (not shown) to the rearward surface 35 of the transom, this ring surrounding the forward portion 36 of the discharge duct 15. Formed integrally with the upper portion of the ring 34 is an upstanding portion 37 from which extends a tubular portion 38, integral therewith, which is set at an angle of 45 degrees to the transom and which extends both fore and aft the transom. The forward part 39 of the portion 38 projects through a suitable aperture 40 in the transom into the interior of the vessel and the rearward part 41 thereof projects in the direction downwardly towards the steering duct 28. The axis 42 of the tubular portion 38, which is thus obliquely disposed with respect to the longitudinal axis 25, is substantially coincident with said common axis 30 The inner periphery 43 of the mounting ring 34 flares radially outwardly in the forward direction as shown at 44, a sealing ring 45 being housed between the flared surface so formed and the exterior surface of the for ward portion 36 of the discharge duct 15. A ring member 46 which fits in an annular recess 47 in the mounting ring 34 retains the sealing ring 45 axially and itself bears against the surface 35 of the transom through the intermediary of a suitable gasket (not shown).

A steering shaft 48 having a steering member 49 fast upon its upper end portion projects downwardly through the tubular portion 38 and at its lower end portion has a drive fitting 50 secured fast thereto. This fitting has a slotted portion 51 internally thereof with which a bushed pin 52 engages. The axis 53 of this pin is offset from, but parallel to, the common axis 42 of the portion 38 and shaft 48. The pin is secured as shown to the forward and upper portion 54 of a cowllike cover member 55 which shrouds the upper parts of the discharge duct and steering duct 28. The cover member is pivotally supported on an outstanding support lug 56, integrally formed on the upper exterior surface of the discharge duct 15, by means of a stud 57, bush 58 and nut 59, whose axis is coincident with the axis 30.

The lowermost parts of the two side portions 60 of the cover member 55 are each integrally provided with an outwardly directed flange 61, both flanges lying parallel to the rearward end face 24 of the discharge duct 15 and the forward end face 29 of the steering duct 28. These flanges 61 are respectively secured by studs 62 and nuts 63 to outwardly directed flanges and formed integrally, and diametrically opposite each other, upon the exterior of the steering duct 28 adjacent the forward end face 29 thereof as shown in FIG. 3.

Suitably secured to a further support lug 65, which is formed integrally with the lower exterior portion of the discharge duct 15 as a local enlargement of the wall thereof, is an outrigger member 66 which projects in cantilever manner externally rearwardly from the external surface of the discharge duct and which is disposed substantially parallelto the longitudinal axis 25. As shown in FIGS. 1 and 3, the member 66 is for the major part of its length substantially spaced from the exterior surface of the steering duct 28. At its rearward end portion this member 66 is provided with a bearing bush 67 which receives a journal sleeve 68, the bush and sleeve together pivotally supporting a stub shaft 69. The shaft 69 is in the form of a stud which is screwthreadedly secured to a lug 70 formed integrally with and extending downwardly from the exterior surface of the steering duct 28. The stud carries a nut 71 for securing the journal sleeve 68 thereto and the axis of the stud, bush and sleeve is coincident with the axis 30.

.A reversing deflector 72 generally of part-cylindrical form 73 and having a pair of side portions 74, is pivotally mounted upon the steering duct 28, the side portions affording the mounting of this deflector upon the duct by way of a pair of pivot pins 75 which have a common horizontal axis 76.

A lever 77 is rigidly mounted at 78 upon the cover member 55 and forms the support for the outer casing of a flexible reverse control cable 79, the inner wire of which is connected to a lever 80 fast with one of the side portions 74 of the reversing deflector 72 as shown in FIGS. 1 and 2. When the reversing deflector is in its inoperative position the part-cylindrical portion 73 thereof is disposed between the upper surfaces of the discharge duct and steering duct and the undersurface of the cover member 55. The flexible cable 79 is connected to an operators reversing control member within the vessel. The steering member 49 is connected by a suitable linkage within the vessel to an operators steering control member adjacent the reversing control member.

In operation of the hydraulic jet propulsion apparatus 10 above described, with the reversing deflector 72 in its inoperative position water drawn in through the intake 18 and the intake duct 11 by the pump 12 and discharged through the discharge duct 15 passes rearwardly from the steering duct 28 in the form of a propulsive jet affording movement of the vessel across the water. For straight-ahead movement of the vessel the steering duct 28 is in the position shown in the drawings, that is, lying on the axis X X as viewed in FIG. 2. Rotary steering movement of the steering shaft 48 by the member 49 is applied through the offset bushed pin 52 to the cover member 55 and to the steering duct 28 bolted thereto, such steering movement being about the common axis 30 of the upper pivot stud 57 and lower pivot stud 69. Since this common axis 30 is at right-angles to the planes containing the circular rearward end face 24 of the discharge duct 15 and the circular forward end face 29 of the steering duct 28, the steering movement at these planes, which are set obliquely to the longitudinal axis 25 of the discharge duct, is purely circular and, by vitrue of the annular axial clearance 31 and the substantial spacing between the major part of the length of the member 66 and the exterior surface of the steering duct 28, without restriction. The range of the steering movement is limited by the engagement of the side portions of the cover member 55 with the exterior side walls of the discharge duct, and in this embodiment this range is 40 on either side of the straight-ahead position of the steering duct 28 shown by line X X in FIG. 2, the limit of steering movement of duct 28 to port being indicated by the line P X and the limit of steering movement of duct 28 to starboard being indicated by the line S X.

It will be understood that the mounting of the steering duct with respect to the discharge duct is such that, upon steering movement, the centre 83 of the elliptically shaped discharge opening of the steering duct 28 moves along an arc.

When it is required to stop the discharge of water from the steering duct 28 in the rearward direction so that the apparatus is effectively in neutral, the reversing deflector 72 is moved downwardly, about its horizontal pivot axis 76, from its inoperative position to an intermediate operative position 72' in which it so deflects the water issuing from the steering duct that it has a downward thrust component. In this way the vessel can be maintained stationary with the pump 12 operating.

If it is subsequently required to reverse the direction of movement of the vessel, the reversing deflector is moved to its fully operative position, that is its lowermost position 72". As the deflector reaches this position, a stop 81 thereon comes into engagement with a stop 82 formed on the under-surface of the cover member 55. In this position of the deflector the water discharged by the steering duct 28 is caused by the deflector to pass forwardly beneath the vessel. Under these conditions steering in reverse is achieved by appropriate operation of the steering shaft 48.

By so pivotally mounting the reversing deflector upon the steering duct, the latter being movable about the axis 30 disposed obliquely to the longitudinal axis 25 of the steering duct, the operation of the apparatus does not rely on movement of the steering duct to extremes of a large rotary range for effecting reverse movement of the vessel. Instead reverse movement is rapidly achieved by appropriate operation of the reversing deflector.

Also by providing support means for the steering duct 28 and drive means for effecting the rotational movement of the steering duct wholly externally of the discharge duct 15, it is not necessary to provide support and drive shafting extending across the interior of the discharge duct and thus the use of such an undesirable obstruction to the flow of water through the duct is avoided.

The term waterborne vessels, hereinbefore used, is intended to include within its scope vessels such as hydrofoil craft and air-cushion vehicles.

We claim:

1. An hydraulic jet propulsion apparatus, suitable for propelling waterborne vessels, including an intake duct, a pump for drawing in water through the intake duct, a discharge duct through which water pumped by said pump passes, a steering duct, support means for said steering duct, whereby that duct is positioned adjacent to and downstream of said discharge duct and water received by the steering duct from the discharge duct discharges to the exterior of the apparatus as a propulsive jet, the end portion of the discharge duct remote from said pump and the end portion of the steering duct adjacent to the discharge duct being both of annular form of substantially the same diameter and spaced the one from the other by means defining a predetermined annular clearance, and said steering duct being capable of rotational movement with respect to the discharge duct about an axis disposed obliquely to and intersecting the longitudinal axis of the discharge duct, thereby to change the direction of the propulsive jet for steering purposes, and drive means including a shaft whose axis is coincident with said obliquelydisposed axis, said shaft being adapted to drive said steering duct, for effecting said rotational movement thereof, about the coincident axis, by way of a slotted drive fitting and associated pin, which pin is offset from but parallel to said coincident axis, and said support means and said drive means being disposed wholly externally of the discharge duct and of the steering duct.

2. An apparatus as claimed in claim 1, wherein said offset pin is mounted fast upon a cover member for the apparatus, said cover member having flanged connections with the external wall of the steering duct.

3. An hydraulic jet propulsion apparatus, suitable for propelling waterborne vessels, including an intake duct, a pump for drawing in water through the intake duct, a discharge duct through which water pumped by said pump passes, a steering duct, support means for said steering duct disposed wholly externally of that duct and of the discharge duct whereby the steering duct is positioned adjacent to and downstream of said discharge duct and water received by the steering duct from the discharge duct discharges to the exterior of the apparatus as a propulsive jet, said support means including an outrigger member, carried upon the exterior surface of the discharge duct, which member (i) projects externally from the discharge duct in cantilever manner in a direction away from said pump, (ii) is disposed substantially parallel to the longitudinal axis of said discharge duct, (iii) is for the major part of its length substantially spaced from the exterior surface of the steering duct, and, (iv) has at its end portion remote from the discharge duct a pivotal connection with said steering duct, the end face of the end portion of the discharge duct remote from said pump and the end face of the end portion of the steering duct adjacent to the discharge duct being of annular form and axially spaced the one from the other by a predetermined clearance, said two adjacent end portions having substantially the same internal cross-sectional dimensions whereby a substantially constant flow area is defined from the said end portion of the discharge duct into said steering duct, and said steering duct being capable of rotational movement with respect to the discharge duct about an axis disposed obliquely to and intersecting the longitudinal axis of the discharge duct, thereby to change the direction of the propulsive jet for steering purposes, and drive means, disposed wholly externally of said discharge duct and of said steering duct, for effecting said rotational movement.

4. An apparatus as claimed in claim 3, wherein a reversing deflector is pivotally mounted upon the steering duct and is movable from an inoperative position to an side portions by which it is pivotally mounted upon the steering duct. 

1. An hydraulic jet propulsion apparatus, suitable for propelling waterborne vessels, including an intake duct, a pump for drawing in water through the intake duct, a discharge duct through which water pumped by said pump passes, a steering duct, support means for said steering duct, wheReby that duct is positioned adjacent to and downstream of said discharge duct and water received by the steering duct from the discharge duct discharges to the exterior of the apparatus as a propulsive jet, the end portion of the discharge duct remote from said pump and the end portion of the steering duct adjacent to the discharge duct being both of annular form of substantially the same diameter and spaced the one from the other by means defining a predetermined annular clearance, and said steering duct being capable of rotational movement with respect to the discharge duct about an axis disposed obliquely to and intersecting the longitudinal axis of the discharge duct, thereby to change the direction of the propulsive jet for steering purposes, and drive means including a shaft whose axis is coincident with said obliquely-disposed axis, said shaft being adapted to drive said steering duct, for effecting said rotational movement thereof, about the coincident axis, by way of a slotted drive fitting and associated pin, which pin is offset from but parallel to said coincident axis, and said support means and said drive means being disposed wholly externally of the discharge duct and of the steering duct.
 2. An apparatus as claimed in claim 1, wherein said offset pin is mounted fast upon a cover member for the apparatus, said cover member having flanged connections with the external wall of the steering duct.
 3. An hydraulic jet propulsion apparatus, suitable for propelling waterborne vessels, including an intake duct, a pump for drawing in water through the intake duct, a discharge duct through which water pumped by said pump passes, a steering duct, support means for said steering duct disposed wholly externally of that duct and of the discharge duct whereby the steering duct is positioned adjacent to and downstream of said discharge duct and water received by the steering duct from the discharge duct discharges to the exterior of the apparatus as a propulsive jet, said support means including an outrigger member, carried upon the exterior surface of the discharge duct, which member (i) projects externally from the discharge duct in cantilever manner in a direction away from said pump, (ii) is disposed substantially parallel to the longitudinal axis of said discharge duct, (iii) is for the major part of its length substantially spaced from the exterior surface of the steering duct, and, (iv) has at its end portion remote from the discharge duct a pivotal connection with said steering duct, the end face of the end portion of the discharge duct remote from said pump and the end face of the end portion of the steering duct adjacent to the discharge duct being of annular form and axially spaced the one from the other by a predetermined clearance, said two adjacent end portions having substantially the same internal cross-sectional dimensions whereby a substantially constant flow area is defined from the said end portion of the discharge duct into said steering duct, and said steering duct being capable of rotational movement with respect to the discharge duct about an axis disposed obliquely to and intersecting the longitudinal axis of the discharge duct, thereby to change the direction of the propulsive jet for steering purposes, and drive means, disposed wholly externally of said discharge duct and of said steering duct, for effecting said rotational movement.
 4. An apparatus as claimed in claim 3, wherein a reversing deflector is pivotally mounted upon the steering duct and is movable from an inoperative position to an operative position in which it changes the direction of a jet of water discharging from the steering duct.
 5. An apparatus as claimed in claim 4, wherein the reversing deflector is of part-cylindrical form having side portions by which it is pivotally mounted upon the steering duct. 